Dental chair



UNITED STATES ATENT FFICE.

ORIEL M. GRAVES, or EUGENE, onncon, AssIenon or ONE-HALF TO r. L. ennvns, or SAME PLACE.

-' DENTALTCHAIR.

SPECIFICATION forming part of Letters Patent No. 284,294, dated September 4 1883, Application filed March 23, 1883. (No model.)

To all whom it may concern.-

Be it known that I, ORIEL M. GRAVES, of Eugene, county of Lane, State of Oregon, have invented an Improved Dentists Chair; and I hereby declare the following'to be a full, clear, and exact description thereof.

My invention relates to a newand useful dentists chair, the various parts of which are so constructed and arranged as to be easily put together or taken apart for transportation.

My invention consists in the construction and arrangement of the parts, and all the necessary adjustments in chairsof this class, as will hereinafter fully appear.

The object of my invention is to provide an inexpensive chair which shall be effective and easilypacked for transportation.

' Referring to the accompanying drawings, Figure 1, Sheet 1, is a perspective view. Fig.

2, Sheet 2, is a vertical section. Fig. 3 is a detail of the seat D.

A represents a short piece of pipe, having cast around it a collar, a, to receive the' legs 13. These are also made of pipe and fit against the face of the collar a, to which they are secured by set-screws b. Asmall shoulder, 1), upon the upper ends of the legs, fits under the base of the collar and prevents the legs from turning sidewise.

C are braces, the ends of which. are turned in both legs and upright A, as in Fig. 2, from which they may be removed when the screws b release the legs from the upright.

D represents the seat, made ofa light frame workof wood and iron, and suitably upholstered-on top Across the seat underneath is a flat shaft, H, (seen in Fig. 3,) the ends of which find bearings in the sides of the frame of the seat. From this shaft extends downwardly the standard E. It fits into the up-.

right pipe A, and is adapted to have a vertical adjustment therein in the following manner: Near the top of thepipe A, on its front, is formed socket f as a bearing for a shaft, G. Between the cavity of the pipe A and the socket f an opening is made, as shown in Fig. 2, so that the shaft may be engaged by the standard. The shaft is provided with holes 9, and the standard with teeth 6, which travel up and down in a vertical slot, cl, in the pipe A, and engage with the holes 9 in the shaft, as seen in Fig. 2. The rotation of the shaft causes the vertical travel of the standard and the raising and lowering of the seat. I11 order to set the standard and seat at any desired point, Ihave the pawl F pivoted to pipe A in such a manner that weight of its longer end will throw its point into any one of aseries of holes, h, made in shaft G. This is shown in Fig. 1. The end of the pawl F is forked, as shown, one point engaging with the holesh, and the other resting outside to bind the shaft and prevent it from turning in that direction. When turned to elevate the standard, the shaft frees itself of the pawl. I11 order to insure the descent of the standard when desired without the inter ference of the pawl, a small sleeve, 1', upon the shaft is held over and covers the holes h by t reason of a spring (not here shown) within the shaft. To draw backthe sleeve, I press outward or downward 011 the ring I, which loosely encircles the crank J, and is connected with the f sleeve 13 by rods k k and elbow-lever j. When the sleeve is withdrawn, the holes h are exposed and thepawl F will engage with them.

The seat D for its inclination turns upon the shaft H, Fig. 3, and is set to position as follows: Hinged suitably to the front of the seat is the front board, K, constructed of a light frame of 'wood and iron. From its back center extends a curved rack, L, with which the edge of a lever, M, engages. This lever is pivoted to a plate or plates, N, secured on top of the standard E, or tothe shaft Hfcurving forwardunder the seat, as shown in Fig. 2.

A spring, 0, secured to the plateN and to the end of lever M, holds said lever in engagement with the rack L. By holding the lever M out of engagement with the rack L the seat may be inclined, as desired, and may be set in place 0 by releasing said lever.

1? represents the back. It is constructed of a light frame-work suitably upholstered. At its bottom center is hinged a plate, 19, which passes down through a bearing, on the back of seat D. A set-screw, 1', binds the plate 19 wherever desired. i

Q are the arms, pivoted to the back but not connected with the seat. They are supported by braces B, Fig. 1, pivoted near their forward ends. These braces extend down to and under the edges of the seat, where they are 2 esaeon Q being pivoted to the back, and the braces It being pivoted to the arms, the adjustment of the back is readily effected.

I S is the head-rest, having a horizontal adj ustment by means of its sliding stem t, and a vertical adjustment by reason of the sliding standard T on the back 1?.

U is the foot-board, hinged suitably to the bottom of the front board, K.

V is the foot-rest. Its sides, near the bottom, are provided with pins it, having large heads. To the sides of the foot-board, near the front, are secured plates 10, having a series of notches,

w. These notches have enlarged bases and openings sufficient to allow the pins a on the chair apart and pack it in small compass for transportation. All the parts are built of as light material as possible and consistent with strength.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-' 1. In a portable dentistschair, the central hollow support, A, and perforated shaft G, in combination with the seat D, standardE, having teeth 6, shaft G, having holes h, the pawl F, engaging with said holes, and the means for regulating the engagement of said pawl, consisting in the sliding sleeve 1', held to cover the holes h, a spring located in shaft G, ring I, and intermediate connecting devices between said ring and sleeve, all constructed to operate substantially as herein described.

'2. In a portable dentists chair, a support ing-base, the seat D, shaft H, journaled under said seat, standard E, braces R, and front board, K, hinged to the seat, in combination with the means for adjusting the inclination of said seat, consisting of the curved rack L and engaging lever M, plate N, and spring 0, substantially as herein described.

3. In a portable dentists chair, the seat D and hinged front board, K, in combination with the back I, hinged to the seat, the arms Q, pivoted to the back plate, I, bearing screw 1', and the connecting-braces It, pivoted to the arms, seat, and front board, all arranged substantially as and for the purpose herein described.

4. In a portable dentists chair, a supporting-base, the hinged foot-board U, having the notched plates w, in combination with the footrest V, having pins a engaging with said plates, and strips 00, pivoted to the foot-board U and to the foot-rest supports, substantially as herein described.

In witness whereof I hereunto set my hand.

0. M. GRAVES.

Witnesses:

I. O. CHILsrRoM, H. D. Gnllvns. 

